1. Field of the Invention
The present invention is related to the use of a natural proteinaceous material that acts as an oil dispersant, in particular an oat protein from which free lipids are removed that emulsifies and disperses oil spills.
2. Background of the Prior Art
When an oil spill occurs, the most desirable remedy is to recover the spilled oil. However, rarely is more than 10% of the oil released in a major spill ultimately recovered. Oil that cannot be recovered may be dispersed, thus protecting shorelines, preventing the oiling of marine birds and mammals, and speeding biodegradation of the oil. One reason why oil dispersal has not been widely used is that dispersants, by and large, are quite toxic.
Furthermore, there is reason to believe that the effectiveness of a surfactant-based dispersant is in direct correlation with its toxicity. A surfactant at a concentration sufficient to emulsify petroleum may also be expected to have a variety of ill effects on marine organisms including tissue irritation, changes in gill membrane permeability that bring on asphyxiation, and increase in uptake of foreign chemicals.
Commercially available oil dispersants are all liquids and possess relatively high LD.sub.50 's. These include Corexit.RTM. 9527 (Exxon), a surfactant-solvent product for oil dispersal; Naxchem.RTM. Dispersant K (formerly known as Conco Dispersant K and now sold by Ruetgers-Nease), a product consisting primarily of surfactants and alcohols; Atlant'ol.RTM. AT-7 (Aspra, Inc.), a water-based product; Omni-Clean.RTM. OSD (Delta Omega Technologies), a water-based product containing synthetic surfactants and fatty acid soaps and marketed as a safe, low-toxicity product; Corexit 9550 (Exxon); and Corexit 7664 (Exxon), a product formerly marketed as an open-sea dispersant but now sold mostly as a beach cleaner.
Surfactants added to oil slicks on water tend to be immediately diluted by the water. Only when sufficient surfactant concentration is present in contact with both water and oil will dispersal occur. Once the surfactant has solubilized the oil, the dispersed droplets mix with greater and greater quantities of water. While this is the desired effect of dispersal, it also tends to dilute the surfactant concentration further, so that resurfacing of oil slicks may occur.
Accordingly, there is a need in the art for an oil spill dispersant that is capable of low energy emulsification of oil spills on water, together with low toxicity.